Hi,l Tobias,
If necessary, it is best to cut back faded or dead foliage in late winter, or as the flowers begin to appear. Since they are in the midst of flowering, and it sounds like they need a bit of a taming, I would now wait until after they are flowering. I'm curious to see them - they are quite large/mature - any chance you could post a photo?
Kathy C
Replied: Wednesday 28th of March 2012 10:18 PM